Retainer and wafer carrier including the same

ABSTRACT

A retainer for a wafer carrier comprising: a body including a plurality of slots configured to receive side surfaces of wafers; and for each of the slots, a supporting structure formed on a sidewall of the slot and configured to make contact with the side surfaces of a corresponding wafer, the supporting structure being spaced apart from an upper corner of the side surface of the corresponding wafer.

CROSS-RELATED APPLICATION

This application claims priority under 35 USC §119 to Korean PatentApplication No. 2014-124723, filed on Sep. 19, 2014 in the KoreanIntellectual Property Office (KIPO), the contents of which are hereinincorporated by reference in their entirety.

BACKGROUND

1. Field

Embodiments relate to a retainer and a wafer carrier including the same.More particularly, example embodiments relate to a retainer arranged ina wafer carrier to support wafers, and a wafer carrier including theretainer.

2. Description of the Related Art

Generally, wafers may be received in a wafer carrier. The wafer carriermay include a front open unified pod (FOUP). The FOUP may include aretainer configured to support the wafers.

According to related arts, a side corner of the wafer may make contactwith the retainer so that the side corner of the wafer may be damaged.Particularly, the side corner of the wafer having a thin thickness maybe more damaged.

SUMMARY

An embodiment includes a retainer for a wafer carrier comprising: a bodyincluding a plurality of slots configured to receive side surfaces ofwafers; and for each of the slots, a supporting structure formed on asidewall of the slot and configured to make contact with the sidesurfaces of a corresponding wafer, the supporting structure being spacedapart from an upper corner of the side surface of the correspondingwafer.

An embodiment includes a wafer carrier comprising: a case having anentrance configured to receive wafers, a first inner surface facing theentrance, and second and third inner surfaces extended from the firstinner surface to the entrance; a door installed at the entrance; andretainers arranged on an inner surface of the door and on each of thefirst to third inner surfaces of the case, each retainer including abody including a plurality of slots configured to receive side surfacesof wafers, each slot including a supporting structure formed on asidewall of the slot and configured to make contact with the sidesurfaces of a corresponding one of the wafers, the supporting structureconfigured to be spaced apart from an upper corner of the side surfaceof the corresponding wafer.

An embodiment includes a retainer for a wafer carrier comprising: a bodyincluding a plurality of slots; and for each of the slots, the slotcomprises: an upper surface; a lower surface; and a supporting structureformed on a sidewall of the slot and protruding into the slot wherein afurthest extent of the protrusion of the supporting structure into theslot is offset from the upper surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings. FIGS. 1to 16 represent non-limiting, example embodiments as described herein.

FIG. 1 is an exploded perspective view illustrating a wafer carrier inaccordance with some embodiments;

FIG. 2 is a plan view illustrating a retainer for supporting a wafer inthe wafer carrier of FIG. 1;

FIG. 3A-3D are cross-sectional views taken along a line III-III′ in FIG.2 according to some embodiments;

FIG. 4 is a cross-sectional view taken along a line IV-IV′ in FIG. 2;

FIG. 5 is a cross-sectional view illustrating a retainer in accordancewith some embodiments;

FIG. 6 is a cross-sectional view illustrating a retainer for supportinga wafer in accordance with some embodiments;

FIG. 7 is a cross-sectional view illustrating a retainer for supportinga wafer in accordance with some embodiments;

FIG. 8 is a cross-sectional view illustrating a retainer of a wafercarrier for supporting a wafer in accordance with some embodiments;

FIG. 9 is a cross-sectional view illustrating a retainer of a wafercarrier for supporting a wafer in accordance with some embodiments;

FIG. 10 is a cross-sectional view illustrating a retainer of a wafercarrier for supporting a wafer in accordance with some embodiments;

FIG. 11 is a plan view illustrating a retainer of a wafer carrier forsupporting a wafer in accordance with some embodiments;

FIG. 12 is a cross-sectional view taken along a line XII-XII′ in FIG.11;

FIG. 13 is a cross-sectional view taken along a line XIII-XIII′ in FIG.2;

FIG. 14 is a plan view illustrating a retainer of a wafer carrier forsupporting a wafer in accordance with example embodiments;

FIG. 15 is a cross-sectional view taken along a line XV-XV′ in FIG. 14;and

FIG. 16 is a cross-sectional view taken along a line XVI-XVI′ in FIG.14.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments will be described more fully hereinafter with reference tothe accompanying drawings, in which particular embodiments are shown.Embodiments may, take many different forms and should not be construedas limited to the particular embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope to those skilled in the art.In the drawings, the sizes and relative sizes of layers and regions maybe exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numerals refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms.

These terms are only used to distinguish one element, component, region,layer or section from another region, layer or section. Thus, a firstelement, component, region, layer or section discussed below could betermed a second element, component, region, layer or section.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent invention. As used herein, the singular forms “a,” “an” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Embodiments are described herein with reference to cross-sectionalillustrations that are schematic illustrations of idealized exampleembodiments (and intermediate structures). As such, variations from theshapes of the illustrations as a result, for example, of manufacturingtechniques and/or tolerances, are to be expected. Thus, exampleembodiments should not be construed as limited to the particular shapesof regions illustrated herein but are to include deviations in shapesthat result, for example, from manufacturing. For example, an implantedregion illustrated as a rectangle will, typically, have rounded orcurved features and/or a gradient of implant concentration at its edgesrather than a binary change from implanted to non-implanted region.Likewise, a buried region formed by implantation may result in someimplantation in the region between the buried region and the surfacethrough which the implantation takes place. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the actual shape of a region of a device andare not intended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, example embodiments will be explained in detail withreference to the accompanying drawings.

FIG. 1 is an exploded perspective view illustrating a wafer carrier inaccordance with some embodiments, FIG. 2 is a plan view illustrating aretainer for supporting a wafer in the wafer carrier of FIG. 1, FIG.3A-3D are cross-sectional views taken along a line III-III′ in FIG. 2according to some embodiments, FIG. 4 is a cross-sectional view takenalong a line IV-IV′ in FIG. 2, FIG. 5 is a cross-sectional viewillustrating a retainer in accordance with some embodiments, FIG. 6 is across-sectional view illustrating a retainer for supporting a wafer inaccordance with some embodiments, and FIG. 7 is a cross-sectional viewillustrating a retainer for supporting a wafer in accordance with someembodiments.

Referring to FIG. 1, a wafer carrier 100 of this embodiment may includea case 110, first retainers 120, second retainers 130 and a door 140.

The case 110 may have an internal space where multiple wafers W may behorizontally received. For clarity, only a single wafer W isillustrated. The case 110 may have an entrance 112 through which thewafers W may be moved. The case 110 may have a rectangularparallelepiped shape. Thus, the case 110 may have a first inner surface114 facing the entrance 112, and a second inner surface 116 and a thirdinner surface 118 extended from the first inner surface 114 to theentrance 112. The second inner surface 116 and the third inner surface118 may have a rounded shape protruding from a central portion of thecase 110 toward an outside of the case 110. Although a rectangularparallelepiped has been used as an example of a shape of the case 110,in other embodiments, the case 110 may have other shapes.

The door 140 may be installed at the entrance 112 of the case 110. Whenthe door 140 is closed, the combination of the case 110 and the door 140may have the rectangular parallelepiped shape.

The first retainers 120 may be arranged on an inner surface of the door140 and the first inner surface 114 of the case 110. In the view of FIG.1, the first retainers 120 on the first inner surface 114 are obscuredby a side of the case 110 with the second inner surface 116; however, asillustrated in FIG. 2, the first retainers 120 on the first innersurface 114 may be opposite the first retainers 120 on the door 140 whenthe door 140 is closed. The second retainers 130 may be arranged on thesecond inner surface 116 and the third inner surface 118 of the case110. As shown in FIG. 2, the first retainers 120 may face each other.Further, the second retainers 130 may face each other. As a result, fourside surfaces of each of the wafers W may be supported by the firstretainers 120 and the second retainers 130.

Referring to FIG. 3A, the first retainer 120 may include a first body122 and a first supporting structure 124. The first body 122 may bearranged on the inner surface of the door 140 and the first innersurface 114 of the case 110. In particular, an outer surface of thefirst body 122 may be fixed to the inner surface of the door 140 and thefirst inner surface 114 of the case 110. The first body 122 may havemultiple first slots 126, each configured to receive a side surface S ofa corresponding one of the wafers W.

The first supporting structure 124 may be formed on an inner surface ofthe first body 122. The first supporting structure 124 may be integrallyformed with the first body 122; however, in other embodiments, the firstsupporting structure 124 may be a separate component that is assembledwith the first body 122. The first body 122 and the first supportingstructure 124 may include a resilient material such as a plastic, arubber, etc.

The first supporting structure 124 may be disposed to make close contactwith the side surface S of the wafer W to support the wafer W. In someembodiments, the first supporting structure 124 may include firstembossings arranged by substantially the same interval in a verticaldirection. The first supporting structure 124 may have a semi-circularshape protruding from the inner surface of the first body 122 in thehorizontal direction. Thus, the first supporting structure 124 may havea rounded surface configured to make point contact with the side surfaceS of the wafer W. The resilient first supporting structure 124, whenmaking contact with the side surface S of the wafer W, may be slightlycompressed to softly support the side surface S of the wafer W.

In addition, because the first supporting structure 124 may have thesemi-circular shape, an upper corner UC of the side surface S of thewafer W may be spaced apart from the first supporting structure 124. Alower corner DC of the side surface S of the wafer W may also be spacedapart from the first supporting structure 124. Thus, only one point ofthe side surface S of the wafer W may make point contact with the firstsupporting structure 124. In contrast, the upper corner UC and the lowercorner DC may not make contact with the first supporting structure 124.As a result, contacts between the sharp upper corner UC and the sharplower corner DC of the wafer W and the first supporting structure 124may be prevented so that the upper corner UC and the lower corner DC ofthe wafer W may not be damaged due to such contact.

Additionally, the misaligned wafer W may be loaded into the internalspace of the case 110. In order to prevent a contact between the uppercorner UC and the lower corner DC of the misaligned wafer W and thefirst supporting structure 124, the first supporting structure 124 mayhave a thickness substantially the same as a thickness of the wafer W.However, the thickness of the first supporting structure 124 may not berestricted within the thickness of the wafer W. The thickness of thefirst supporting structure 124 may vary within the non-contact betweenthe upper corner UC and the lower corner DC of the wafer W and the firstsupporting structure 124.

In an embodiment, the slot 126 may be bounded by a lower surface 126Land an upper surface 126U. The lower surface 126L may be configured tosupport a back side of the wafer W. The first supporting structure 124may be configured to extend into the slot 126 from the first body 122. Afurthest extent of the first supporting structure 124 extending into theslot may be offset from one or more of the lower surface 126L and theupper surface 126U. In this embodiment, the furthest extent of the firstsupporting structure 124 is offset from both the lower surface 126L andthe upper surface 126U. In particular, the upper corner UC and the lowercorner DC of the wafer W may be disposed closer to the upper surface126U and the lower surface 126L when a wafer W is loaded. Because thefurthest extent of the first supporting structure 124 is offset fromboth the lower surface 126L and the upper surface 126U, the firstsupporting structure 124 may contact the wafer W only on the sidesurface S at a location offset from the upper corner UC and the lowercorner DC.

Referring to FIG. 3B, the first retainer 120′ may include structuressimilar to the first retainer 120 of FIG. 3A. In particular, the firstsupporting structure 124′ may be similar to the first supportingstructure 124; however, the first supporting structure 124′ may have adifferent shape. In this embodiment, the first supporting structure 124′has a triangular shape. Accordingly, the first supporting structure 124′may still make point contact with only one point of the side surface Sof the wafer W. Although a triangular shape and a semi-circular shapehave been used as examples, any structure that may make point contactwith only one point of the side surface S of the wafer W at a pointbetween the upper corner UC and the lower corner DC may be used.

Referring to FIG. 3C, the first retainer 120″ may include structuressimilar to the first retainer 120 of FIG. 3A. In particular, the firstsupporting structure 124″ may be similar to the first supportingstructure 124; however, the first supporting structure 124″ may have adifferent shape. In this embodiment, the first supporting structure 124″has a trapezoid shape. In particular, the first supporting structure124″ a surface SS that is configured to contact the side surface S ofthe wafer W. However, the contact between the side surface S of thewafer W and the surface SS of the first supporting structure 124″ doesnot extend to the upper corner UC and the lower corner DC. Although atrapezoid has been used as an example, any shape that makes surfacecontact with the side surface S of the wafer W that does not extend tothe upper corner UC and the lower corner DC may be used.

Referring to FIG. 3D, the first retainer 120′″ may include structuressimilar to the first retainer 120 of FIG. 3A. In particular, the firstsupporting structure 124′″ may be similar to the first supportingstructure 124; however, the first supporting structure 124′″ may have adifferent shape. In this embodiment, the first supporting structure124′″ has a ribbed shape. As a result, the first supporting structure124′″ may be configured to make point contact with the side surface S ofthe wafer W at multiple locations. However, each of these point contactsmay be offset from the upper corner UC and the lower corner DC. Althougha first supporting structure 124′″ configured to have up to three pointcontacts has been used as an example, a structure configured to have anynumber of point contacts may be used as the first supporting structure124′″ as long as the point contact are offset from the upper corner UCand the lower corner DC. In addition, although multiple point contactshave been illustrated as the result of ribs with each having atriangular shape, the shape of the individual ribs may be similar tothat of a structure configured to create a single point contact. Forexample, each rib may have a semi-circular shape.

Although a variety of shapes have been given as examples of the firstsupporting structure 124, any shape that results in contact with theside surface S of the wafer W that is offset from the upper corner UCand the lower corner DC may be used. Furthermore, other embodiments willbe described below using a first supporting structure 124, withmodifications to a first supporting structure 124, having a structuresimilar to the first supporting structure 124, or the like. In suchembodiments, the example of the semi-circular first supporting structure124 may be replaced with first supporting structures 124 havingdifferent shapes as described above.

Referring to FIG. 4, the second retainer 130 may have a structuresubstantially the same as the structure of the first retainer 120.Because the second inner surface 116 and the third inner surface 118 ofthe case 110 may have the rounded shape protruding from the centralportion of the case 110 toward the outside of the case 110, the secondretainer 130 may also have a rounded shape protruding toward the secondinner surface 116 and the third inner surface 118 of the case 110.

The second retainer 130 may include a second body 132 and a secondsupporting structure 134. The second body 132 may be arranged on thesecond inner surface 116 and the third inner surface 118 of the case110. The second body 132 may have multiple second slots 136, eachconfigured to receive a side surface S of a corresponding one of thewafers W.

In some embodiments, the second supporting structure 134 may includesecond embossings formed on an inner surface of the second body 132. Thesecond supporting structure 134 may be integrally formed with the secondbody 132; however, in other embodiments, the second supporting structure134 may be a separate component that is assembled with the second body132. The second body 132 and the second supporting structure 134 mayinclude a resilient material such as a plastic, a rubber, etc. Thesecond supporting structure 134 may have a shape and functionssubstantially the same as the shape and the functions of the firstsupporting structure 124. Thus, any further illustrations with respectto the second supporting structure 134 may be omitted herein forbrevity.

Alternatively, referring to FIG. 5, the first supporting structure 124may have a hollow portion 128. Thus, the first supporting structure 124may have a hollow structure having a hollow inner space. The resilientfirst supporting structure 124 making contact with the side surface S ofthe wafer W may be compressed into the hollow portion 128 to more softlysupport the side surface S of the wafer W. Similarly, the secondsupporting structure 134 may also have a hollow portion.

The first retainer 120 and the second retainer 130 may be configured tosupport a wafer in FIG. 6. The wafer in FIG. 6 may include a carrierwafer CW1 and a device wafer

DW1. The device wafer DW1 may be attached to an upper surface of thecarrier wafer CW1 using an adhesive. The carrier wafer CW1 may include abare wafer without electronic devices. In contrast, the device wafer DW1may include electronic devices. The device wafer DW1 may have a sidesurface DS1 substantially coplanar with a side surface CS1 of thecarrier wafer CW1.

In some embodiments, the device wafer DW1 may include multiple plugs P.The plugs P may be formed in the device wafer DW1 in a verticaldirection. The plugs P may be electrically connected between an uppersemiconductor chip and a lower semiconductor chip of a multi-chippackage. The plugs P may electrically make contact with conductive bumpsof the upper semiconductor chip. Thus, the plugs P may have upper endsexposed through an upper surface of the device wafer DW1. The uppersurface of the device wafer DW1 may be removed by a grinding processuntil the upper ends of the plugs P may be exposed. During the grindingprocess, the carrier wafer CW1 may support the device wafer DW1. As aresult, the device wafer DW1 may have a thickness less than a thicknessof the carrier wafer CW1. Thus, an upper corner UC1 of the thin devicewafer DW1 may be easily damaged. In order to prevent the damage of theupper corner UC1 of the device wafer DW1 a trimming process forpartially removing the upper corner UC1 of the device wafer DW1 may beperformed.

However, in some embodiments, the first supporting structure 124 maymake point contact with only the side surface CS1 of the carrier waferCW1. The first supporting structure 124 may be spaced apart from theupper corner UC1 of the side surface DS1 of the device wafer DW1.Further, the first supporting structure 124 may be spaced apart from alower corner DC1 of a side surface CS1 of the carrier wafer CW1. Thus,the sharp upper corner UC1 of the device wafer DW1 and the sharp lowercorner DC1 of the carrier wafer CW1 may not make contact with the firstsupporting structure 124 so that the upper corner UC1 of the devicewafer DW1 and the lower corner DC1 of the carrier wafer CW1 may not bedamaged. As a result, the trimming process for partially removing theside surface DS1 of the device wafer DW1 may not be performed.

The first retainer 120 and the second retainer 130 may be configured tosupport a wafer in FIG. 7. The wafer in FIG. 7 may include a carrierwafer CW2 and a device wafer DW2. The carrier wafer CW2 and the devicewafer DW2 in FIG. 7 may have structures substantially similar to thestructures of the carrier wafer CW1 and the device wafer DW1 in FIG. 6,respectively, except for a side surface DS2 of the device wafer DW2.Thus, any further illustrations of substantially similar aspects of thecarrier wafer CW2 and the device wafer DW2 in FIG. 7 may be omittedherein for brevity.

The side surface DS2 of the device wafer DW2 may be positioned nearer toa central portion of the carrier wafer CW2 with respect to a sidesurface CS2 of the carrier wafer CW2. For example, a trimming processmay be performed on the side surface DS2 of the device wafer DW2 so thatthe side surface DS2 of the device wafer DW2 may be positioned nearer toa central portion of the carrier wafer CW2 with respect to a sidesurface CS2 of the carrier wafer CW2.

The device wafer DW2 may be attached to an upper surface of the carrierwafer CW2 using an adhesive. The carrier wafer CW2 may include a barewafer without electronic devices. In contrast, the device wafer DW2 mayinclude electronic devices. A sharp upper corner UC2 of the device waferDW2 and a sharp lower corner DC2 of the carrier wafer CW2 may not makecontact with the first supporting structure 124 so that the upper cornerUC2 of the device wafer DW2 and the lower corner DC2 of the carrierwafer CW2 may not be damaged.

FIG. 8 is a cross-sectional view illustrating a retainer of a wafercarrier for supporting a wafer in accordance with some embodiments, FIG.9 is a cross-sectional view illustrating a retainer of a wafer carrierfor supporting a wafer in accordance with some embodiments, and FIG. 10is a cross-sectional view illustrating a retainer of a wafer carrier forsupporting a wafer in accordance with some embodiments.

Referring to FIG. 8, a retainer 220 of this example embodiment mayinclude a body 222 and a supporting structure 224. The body 222 may havemultiple slots 226, each configured to receive side surfaces S of acorresponding wafer W.

In some embodiments, the supporting structure 224 may include asupporting surface. The supporting structure 224 may be configured topartially make face contact with the side surface S of the wafer W.Thus, the supporting surface of the supporting structure 224 may beconfigured to have a thickness less than a thickness of the wafer W. Thesupporting surface of the supporting structure 224 may be configured tobe substantially parallel to the side surface S of the wafer W. Thesupporting structure 224 may be configured to make face contact withless than all of the side surface S of the wafer W. In addition, thesupporting structure 224 may be configured to not make contact with theupper corner UC and the lower corner DC of the wafer W. That is thesupporting surface of the supporting structure 224 may be offset fromthe upper corner UC and the lower corner DC of the wafer W.

Additionally, the body 222 may further include a first receiving groove227 and a second receiving groove 228. The first receiving groove 227may be configured to extend from the slot 226 to expose the upper cornerUC of the wafer W. The second receiving groove 228 may be configured toextend from the slot 226 to expose the lower corner DC of the wafer W.Because the upper corner UC of the wafer W may be exposed through thefirst receiving groove 227 and the lower corner DC of the wafer W may beexposed through the second receiving groove 228, contacts between theupper corner UC and the supporting structure 224, and between the lowercorner DC of the supporting structure 224 may be prevented. In someembodiments, the first receiving groove 227 and the second receivinggroove 228 may have a circular shape. Alternatively, the first receivinggroove 227 and the second receiving groove 228 may have other shapessuch that the upper corner UC and the supporting structure 224 do notcontact and the lower corner DC and the supporting structure 224 do notcontact.

The retainer 220 may be configured to support a wafer in FIG. 9. Thewafer in FIG. 9 may have a structure substantially the same as thestructure of the wafer including the carrier wafer CW1 and the devicewafer DW1 in FIG. 6. Thus, any further description of similar aspects ofthe wafer in FIG. 9 may be omitted herein for brevity.

The supporting structure 224 may be configured to partially make facecontact with the side surface CS1 of the carrier wafer CW1. Thesupporting structure 224 may be configured to be substantially parallelto the side surface CS1 of the carrier wafer CW1.

The supporting structure 224 may be configured to make face contact withless than all of the side surface CS1 of the carrier wafer CW1. In someembodiments, the supporting structure 224 may be configured to make facecontact with both a portion of the side surface CS1 of the carrier waferCW1 and the side surface DS1 of the device wafer DW1. However, thesupporting structure 224 may be configured to not make contact with allof the side surface DS1 of the device wafer DW1. Thus, the supportingstructure 224 may be configured to not make contact with the uppercorner UC1 of the device wafer DW1 and the lower corner DC1 of thecarrier wafer CW1.

The upper corner UC1 of the device wafer DW1 may be exposed through thefirst receiving groove 227. The lower corner DC1 of the carrier waferCW1 may be exposed through the second receiving groove 228. Therefore,the contacts between the upper corner UC1 of the device wafer DW1 andthe supporting structure 224 and between the lower corner DC1 of thecarrier wafer CW1 and the supporting structure 224 may be prevented.

The retainer 220 may be configured to support a wafer in FIG. 10. Thewafer in FIG. 10 may have a structure substantially the same as thestructure of the wafer including the carrier wafer CW2 and the devicewafer DW2 in FIG. 7. Thus, any further description of similar featuresof the wafer in FIG. 10 may be omitted herein for brevity.

The supporting structure 224 may partially make face contact with theside surface CS2 of the carrier wafer CW2. The supporting surface of thesupporting structure 224 may be configured to be substantially parallelto the side surface CS2 of the carrier wafer CW2.

The supporting structure 224 may be configured to make face contact witha partial of the side surface CS2 of the carrier wafer CW2. In contrast,the supporting structure 224 may be configured to not make contact withthe side surface DS2 of the device wafer DW2. Thus, the supportingstructure 224 may be configured to not make contact with the uppercorner UC2 of the device wafer DW2 and the lower corner DC2 of thecarrier wafer CW2.

The upper corner UC2 of the device wafer DW2 may be exposed through thefirst receiving groove 227. The lower corner DC2 of the carrier waferCW2 may be exposed through the second receiving groove 228. Therefore,the contacts between the upper corner UC2 of the device wafer DW2 andthe supporting structure 224 and between the lower corner DC2 of thecarrier wafer CW2 and the supporting structure 224 may be prevented.

FIG. 11 is a plan view illustrating a retainer of a wafer carrier forsupporting a wafer in accordance with some embodiments, FIG. 12 is across-sectional view taken along a line XII-XII′ in FIG. 11, and FIG. 13is a cross-sectional view taken along a line XIII-XIII′ in FIG. 2.

Referring to FIG. 11, first retainers 320 may be arranged on the innersurface of the door 140 and the first inner surface 114 of the case. Thesecond retainers 330 may be arranged on the second inner surface 116 andthe third inner surface 118 of the case. Thus, four side surfaces of thewafer W may be supported by the first retainers 320 and the secondretainers 330.

Referring to FIG. 12, the first retainer 320 may have a structuresubstantially the same as the structure of the first retainer 120 inFIG. 3. The first retainer 320 may include a first body 322 and asupporting structure 324. The first body 322 may include a plurality offirst slots 326 configured to receive side surfaces S of the wafers W.The supporting structure 324 may have a semi-circular shape protrudedfrom an inner surface of the first body 322 in the horizontal directionto make point contact with the side surface of the wafer W, or anotherstructure as described above.

Referring to FIG. 13, the second retainer 330 may include a second body332 and a supporting structure 334. The second body 332 may includemultiple second slots 336, each configured to receive the side surfacesS a corresponding one of the wafers S.

The supporting structure 334 may be configured to partially make facecontact with the side surface S of the wafer W. The supporting surfaceof the supporting structure 334 may have a thickness less than athickness of the wafer W. The supporting surface of the supportingstructure 334 may be configured to be substantially parallel to the sidesurface S of the wafer W. The supporting structure 334 may be configuredto make face contact with a partial of the side surface S of the waferW. In contrast, the supporting structure 334 may be configured to notmake contact with the upper corner UC and the lower corner DC of thewafer W.

Additionally, the second body 332 may further include a first receivinggroove 337 and a second receiving groove 338. The first receiving groove337 may be configured to extend from the second slot 336 to expose theupper corner UC of the wafer W. The second receiving groove 338 may beconfigured to extend from the second slot 336 to expose the lower cornerDC of the wafer W. Because the upper corner UC of the wafer W may beexposed through the first receiving groove 337 and the lower corner DCof the wafer W may be exposed through the second receiving groove 338,contacts between the upper corner UC and the supporting structure 334,and between the lower corner DC of the supporting structure 334 may beprevented.

Alternatively, the first retainer 320 may include the supportingstructure 334. The second retainer 330 may include the supportingstructure 324. Further, the first retainer 320 and the second retainer330 may be configured to support the wafer in FIG. 6 or the wafer inFIG. 7.

FIG. 14 is a plan view illustrating a retainer of a wafer carrier forsupporting a wafer in accordance with some embodiments, FIG. 15 is across-sectional view taken along a line XV-XV′ in FIG. 14, and FIG. 16is a cross-sectional view taken along a line XVI-XVI′ in FIG. 14.

Referring to FIG. 14, first retainers 420 may be arranged on the innersurface of the door 140 and the first inner surface 114 of the case. Thesecond retainers 430 may be arranged on the second inner surface 116 andthe third inner surface 118 of the case. Thus, four side surfaces of thewafer W may be supported by the first retainers 420 and the secondretainers 430.

Referring to FIG. 15, the first retainer 420 may have a structuresubstantially the same as the structure of the first retainer 120 inFIG. 3. The first retainer 420 may include a first body 422 and asupporting surface 424. The first body 422 may include multiple firstslots 426, each configured to receive side surfaces S a correspondingone of the wafers W. The supporting surface 424 may have a semi-circularshape protruded from an inner surface of the first body 422 in thehorizontal direction to make point contact with the side surface of thewafer W.

Referring to FIG. 16, the second retainer 430 may include a second body432 including multiple second slots 436, each configured to receive theside surfaces S a corresponding one of the wafers S. However, theembossing, the supporting surface, or other supporting structure may notbe formed on the sidewalls of the second slots 436.

Alternatively, the first retainer 420 and the second retainer 430 may beconfigured to support the wafer in FIG. 6 or the wafer in FIG. 7.

According to example embodiments, the supporting structure may be spacedapart from the upper corner and the lower corner of the side surface ofthe wafer so that the supporting structure may not make contact with thecorners of the side surface of the wafer. Thus, the side surface of thewafer may not be damaged. Particularly, because the corners of the sidesurface of the thin device wafer including the plugs may not makecontact with the supporting structure, the side corners of the sidesurface of the thin device wafer may not be damaged. As a result, it maynot be required to perform a trimming process for partially removing theside surface of the device wafer in order to prevent damages of the sidesurface of the thin device wafer.

Some embodiments include a retainer capable of preventing damages of aside corner of a wafer.

Some embodiments include a wafer carrier including the above-mentionedretainer.

Some embodiments include a retainer for a wafer carrier. The retainermay include a body and a supporting structure. The body may be arrangedon an inner surface of a wafer carrier configured to receive a pluralityof wafers. The body may have a plurality of slots configured to receivea side surface of each of the wafers. The supporting structure may beformed on a sidewall of each of the slots. The supporting structure maymake contact with the side surface of each of the wafers. The supportingstructure may be spaced apart from an upper corner of the side surfaceof each of the wafers.

In some embodiments, the supporting structure may be spaced apart from alower corner of the side surface of each of the wafers.

In some embodiments, the supporting structure may have a rounded surfaceconfigured to make point contact with the side surface of each of thewafers.

In some embodiments, the supporting structure may include at least oneembossing having the rounded surface.

In some embodiments, the embossing may have a hollow structure.

In some embodiments, the supporting structure may have a supportingsurface configured to partially make face contact with the side surfaceof each of the wafers.

In some embodiments, the supporting surface may be parallel to the sidesurface of each of the wafers.

In some embodiments, the supporting surface may have a thickness lessthan a thickness of the wafer.

In some embodiments, the body may have a first receiving grooveconnected to the slot to expose the upper corner of the wafer and anupper end of the supporting surface.

In some embodiments, the body may have a second receiving grooveconnected to the slot to expose the lower corner of the wafer and alower end of the supporting surface.

In some embodiments, the supporting structure may include a resilientmaterial.

In some embodiments, the supporting structure may be integrally formedwith the body.

In some embodiments, the wafer may include a carrier wafer and a devicewafer. The device wafer may be attached to the carrier wafer. The devicewafer may include plugs formed in the device wafer.

In some embodiments, the device wafer may have a side surfacesubstantially coplanar with a side surface of the carrier wafer.

In some embodiments, the device wafer may have a side surface inside theside surface of the carrier wafer toward a central portion of thecarrier wafer.

Some embodiments include a retainer for a wafer carrier. The retainermay include a body and an embossing. The body may be arranged on aninner surface of a wafer carrier configured to receive carrier wafersand device wafers. Each of the device wafers may be attached to each ofthe carrier wafers. Each of the device wafers may include plugs formedin each of the device wafers. The body may include a plurality of slotsconfigured to receive side surfaces of the carrier wafers and the devicewafers. The embossing may be formed on a sidewall of each of the slots.The embossing may make point contact with the side surface of each ofthe carrier wafers. The embossing may be spaced apart from an uppercorner of each of the device wafers.

In some embodiments, the device wafer may have a side surfacesubstantially coplanar with a side surface of the carrier wafer.

In some embodiments, the embossing may be spaced apart from a lowercorner of the carrier wafer.

In some embodiments, the embossing may include a resilient material.

In some embodiments, the embossing may have a hollow structure.

Some embodiments include a wafer carrier. The wafer carrier may includea case, a door and retainers. The case may include an entrance throughwhich wafers may be moved, a first inner surface facing the entrance,second and third inner surfaces extended from the first inner surface tothe entrance. The door may be arranged at the entrance. Each of theretainers may include a body and a supporting structure. The body may bearranged on the first to third inner surfaces of the case. The body mayhave a plurality of slots configured to receive side surfaces of thewafers. The supporting structure may be formed on a sidewall of each ofthe slots. The supporting structure may make contact with the sidesurface of each of the wafers. The supporting structure may be spacedapart from an upper corner of the side surface of each of the wafers.

In some embodiments, the supporting structure may be spaced apart from alower corner of the side surface of each of the wafers.

In some embodiments, the supporting structure may include at least oneembossing configured to make point contact with the side surface of thewafer.

In some embodiments, the supporting structure may have a supportingsurface configured to partially make face contact with the side surfaceof the wafer.

In some embodiments, the body may have a first receiving grooveconnected to the slot to expose the upper corner of the wafer and anupper end of the supporting surface, and a second receiving grooveconnected to the slot to expose the lower corner of the wafer and alower end of the supporting surface.

In some embodiments, the retainers on the second and third innersurfaces may have a rounded shape protruded toward the second thirdinner surface of the case.

In some embodiments, the wafer may include a carrier wafer and a devicewafer. The device wafer may be attached to the carrier wafer. The devicewafer may include plugs formed in the device wafer. The device wafer mayhave a side surface substantially coplanar with a side surface of thecarrier wafer.

Some embodiments include a wafer carrier. The wafer carrier may includea case, a door and a first retainer and a second retainer. The case mayinclude an entrance through which wafers may be moved, a first innersurface facing the entrance, second and third inner surfaces extendedfrom the first inner surface to the entrance. The door may be arrangedat the entrance. The first retainer may include a body and a supportingstructure. The body may be arranged on the first inner surface of thecase and an inner surface of the door. The body may have a plurality offirst slots configured to receive side surfaces of the wafers. Thesupporting structure may be formed on a sidewall of each of the firstslots. The supporting structure may make contact with the side surfaceof each of the wafers. The supporting structure may be spaced apart froman upper corner of the side surface of each of the wafers. The secondretainer may be arranged on the second and third inner surfaces of thecase. The second retainer may have a plurality of second slotsconfigured to receive the side surfaces of the wafers.

In some embodiments, the second retainer may have a supporting surfaceformed on side walls of the second slots to partially make face contactwith the side surface of the wafer.

In some embodiments, the second retainer may have a first receivinggroove connected to the slot to expose the upper corner of the wafer andan upper end of the supporting surface, and a second receiving grooveconnected to the slot to expose the lower corner of the wafer and alower end of the supporting surface.

In some embodiments, the second retainer may have a rounded shapeprotruded toward the second third inner surface of the case.

In some embodiments, the wafer may include a carrier wafer and a devicewafer. The device wafer may be attached to the carrier wafer. The devicewafer may include plugs formed in the device wafer. The device wafer mayhave a side surface substantially coplanar with a side surface of thecarrier wafer.

In some embodiments, the supporting structure may be spaced apart fromthe upper corner and the lower corner of the side surface of the waferso that the supporting structure may not make contact with the cornersof the side surface of the wafer. Thus, the side surface of the wafermay not be damaged. Particularly, because the corners of the sidesurface of the thin device wafer including the plugs may not makecontact with the supporting structure, the side corners of the sidesurface of the thin device wafer may not be damaged. As a result, it maynot be required to perform a trimming process for partially removing theside surface of the device wafer in order to prevent damages of the sidesurface of the thin device wafer

The foregoing is illustrative of example embodiments and is not to beconstrued as limiting thereof. Although a few example embodiments havebeen described, those skilled in the art will readily appreciate thatmany modifications are possible in the example embodiments withoutmaterially departing from the novel teachings and advantages of thepresent invention. Accordingly, all such modifications are intended tobe included within the scope of the present invention as defined in theclaims. In the claims, means-plus-function clauses are intended to coverthe structures described herein as performing the recited function andnot only structural equivalents but also equivalent structures.Therefore, it is to be understood that the foregoing is illustrative ofvarious example embodiments and is not to be construed as limited to thespecific example embodiments disclosed, and that modifications to thedisclosed example embodiments, as well as other example embodiments, areintended to be included within the scope of the appended claims.

What is claimed is:
 1. A retainer for a wafer carrier comprising: a bodyincluding a plurality of slots configured to receive side surfaces ofwafers; and for each of the slots, a supporting structure formed on asidewall of the slot and configured to make contact with the sidesurfaces of a corresponding wafer, the supporting structure being spacedapart from an upper corner of the side surface of the correspondingwafer.
 2. The retainer for a wafer carrier of claim 1, wherein for atleast one of the slots, the supporting structure is spaced apart from alower corner of the side surface of the corresponding wafer.
 3. Theretainer for a wafer carrier of claim 1, wherein for at least one of theslots, the supporting structure has a rounded surface configured to makepoint contact with the side surface of the corresponding wafer.
 4. Theretainer for a wafer carrier of claim 3, wherein for the at least one ofthe slots, the supporting structure comprises an embossing having therounded surface.
 5. The retainer for a wafer carrier of claim 1, whereinfor at least one of the slots, the supporting structure has a hollowstructure.
 6. The retainer for a wafer carrier of claim 1, wherein forat least one of the slots, the supporting structure comprises asupporting surface configured to partially make face contact with theside surface of the corresponding wafer.
 7. The retainer for a wafercarrier of claim 6, wherein for the at least one of the slots, thesupporting surface is substantially parallel to the side surface of thecorresponding wafer.
 8. The retainer for a wafer carrier of claim 1,wherein for at least one of the slots, the body further comprises afirst receiving groove connected to the slot and configured to exposethe upper corner of the corresponding wafer and an upper end of thesupporting structure.
 9. The retainer for a wafer carrier of claim 8,wherein for the at least one of the slots, the body further comprises asecond receiving groove connected to the slot and configured to expose alower corner of the corresponding wafer and a lower end of thesupporting structure.
 10. The retainer for a wafer carrier of claim 1,wherein for at least one of the slots, the supporting structurecomprises a resilient material.
 11. The retainer for a wafer carrier ofclaim 1, wherein for at least one of the slots, the supporting structureis integrally formed with the body.
 12. The retainer for a wafer carrierof claim 1, wherein each of the wafers comprises: a carrier wafer; and adevice wafer attached to the carrier wafer, the device wafer having aside surface substantially coplanar with a side surface of the carrierwafer.
 13. The retainer for a wafer carrier of claim 1, wherein each ofthe wafers comprises: a carrier wafer; and a device wafer attached tothe carrier wafer, the device wafer having a side surface closer to acentral portion of the carrier wafer than a side surface of the carrierwafer.
 14. A wafer carrier comprising: a case having an entranceconfigured to receive wafers, a first inner surface facing the entrance,and second and third inner surfaces extended from the first innersurface to the entrance; a door installed at the entrance; and retainersarranged on an inner surface of the door and on each of the first tothird inner surfaces of the case, each retainer including a bodyincluding a plurality of slots configured to receive side surfaces ofwafers, each slot including a supporting structure formed on a sidewallof the slot and configured to make contact with the side surfaces of acorresponding one of the wafers, the supporting structure configured tobe spaced apart from an upper corner of the side surface of thecorresponding wafer.
 15. The wafer carrier of claim 14, whereinstructures of the slots of the retainer on the inner surface of the doorare different from structures of the slots of the retainers on thesecond and third inner surfaces.
 16. The wafer carrier of claim 14,wherein the retainers on the second and third inner surfaces of the casehave a rounded shape protruding towards the corresponding second orthird surface.
 17. A retainer for a wafer carrier comprising: a bodyincluding a plurality of slots; and for each of the slots, the slotcomprises: an upper surface; a lower surface; and a supporting structureformed on a sidewall of the slot and protruding into the slot wherein afurthest extent of the protrusion of the supporting structure into theslot is offset from the upper surface.
 18. The retainer for a wafercarrier of claim 17, wherein for at least one of the slots, the furthestextent of the protrusion of the supporting structure into the slot isoffset from the lower surface.
 19. The retainer for a wafer carrier ofclaim 17, wherein for at least one of the slots, the furthest extent ofthe protrusion of the supporting structure is a surface.
 20. Theretainer for a wafer carrier of claim 17, wherein for at least one ofthe slots, the slot further comprises a groove disposed at a corner ofthe upper surface and the sidewall.